diff --git a/lib/astutils.cpp b/lib/astutils.cpp
index 19e1e46e1..63f002645 100644
--- a/lib/astutils.cpp
+++ b/lib/astutils.cpp
@@ -445,6 +445,36 @@ static void followVariableExpressionError(const Token *tok1, const Token *tok2,
     errors->push_back(item);
 }
 
+template<class Predicate, class F>
+static void findTokenValue(const Token* const tok, Predicate pred, F f)
+{
+    auto x = std::find_if(tok->values().begin(), tok->values().end(), pred);
+    if (x != tok->values().end())
+        f(*x);
+}
+
+bool isEqualKnownValue(const Token * const tok1, const Token * const tok2)
+{
+    bool result = false;
+    findTokenValue(tok1, std::mem_fn(&ValueFlow::Value::isKnown), [&](const ValueFlow::Value& v1) {
+        findTokenValue(tok2, std::mem_fn(&ValueFlow::Value::isKnown), [&](const ValueFlow::Value& v2) {
+            result = v1.equalValue(v2);
+        });
+    });
+    return result;
+}
+
+bool isDifferentKnownValues(const Token * const tok1, const Token * const tok2)
+{
+    bool result = false;
+    findTokenValue(tok1, std::mem_fn(&ValueFlow::Value::isKnown), [&](const ValueFlow::Value& v1) {
+        findTokenValue(tok2, std::mem_fn(&ValueFlow::Value::isKnown), [&](const ValueFlow::Value& v2) {
+            result = !v1.equalValue(v2);
+        });
+    });
+    return result;
+}
+
 bool isSameExpression(bool cpp, bool macro, const Token *tok1, const Token *tok2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
 {
     if (tok1 == nullptr && tok2 == nullptr)
@@ -464,6 +494,8 @@ bool isSameExpression(bool cpp, bool macro, const Token *tok1, const Token *tok2
     if (Token::simpleMatch(tok2, "!") && Token::simpleMatch(tok2->astOperand1(), "!") && !Token::simpleMatch(tok2->astParent(), "=")) {
         return isSameExpression(cpp, macro, tok1, tok2->astOperand1()->astOperand1(), library, pure, followVar, errors);
     }
+    if (tok1->str() != tok2->str() && isDifferentKnownValues(tok1, tok2))
+        return false;
     // Follow variable
     if (followVar && tok1->str() != tok2->str() && (Token::Match(tok1, "%var%") || Token::Match(tok2, "%var%"))) {
         const Token * varTok1 = followVariableExpression(tok1, cpp, tok2);
@@ -596,16 +628,6 @@ bool isSameExpression(bool cpp, bool macro, const Token *tok1, const Token *tok2
     return commutativeEquals;
 }
 
-bool isEqualKnownValue(const Token * const tok1, const Token * const tok2)
-{
-    return tok1->hasKnownValue() && tok2->hasKnownValue() && tok1->values() == tok2->values();
-}
-
-bool isDifferentKnownValues(const Token * const tok1, const Token * const tok2)
-{
-    return tok1->hasKnownValue() && tok2->hasKnownValue() && tok1->values() != tok2->values();
-}
-
 static bool isZeroBoundCond(const Token * const cond)
 {
     if (cond == nullptr)
diff --git a/lib/valueflow.h b/lib/valueflow.h
index 2bc84fbea..d9fc94dc1 100644
--- a/lib/valueflow.h
+++ b/lib/valueflow.h
@@ -60,7 +60,7 @@ namespace ValueFlow {
         {}
         Value(const Token *c, long long val);
 
-        bool operator==(const Value &rhs) const {
+        bool equalValue(const ValueFlow::Value& rhs) const {
             if (valueType != rhs.valueType)
                 return false;
             switch (valueType) {
@@ -95,6 +95,12 @@ namespace ValueFlow {
                 if (tokvalue != rhs.tokvalue)
                     return false;
             }
+            return true;
+        }
+
+        bool operator==(const Value &rhs) const {
+            if (!equalValue(rhs))
+                return false;
 
             return varvalue == rhs.varvalue &&
                    condition == rhs.condition &&
@@ -105,6 +111,10 @@ namespace ValueFlow {
                    valueKind == rhs.valueKind;
         }
 
+        bool operator!=(const Value &rhs) const {
+            return !(*this == rhs);
+        }
+
         std::string infoString() const;
 
         enum ValueType { INT, TOK, FLOAT, MOVED, UNINIT, CONTAINER_SIZE, LIFETIME, BUFFER_SIZE } valueType;
diff --git a/test/testother.cpp b/test/testother.cpp
index 030ca96c9..73726c00e 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -137,6 +137,7 @@ private:
         TEST_CASE(duplicateExpression6); // ticket #4639
         TEST_CASE(duplicateExpression7);
         TEST_CASE(duplicateExpression8);
+        TEST_CASE(duplicateExpression9); // #9320
         TEST_CASE(duplicateExpressionLoop);
         TEST_CASE(duplicateValueTernary);
         TEST_CASE(duplicateExpressionTernary); // #6391
@@ -4584,6 +4585,16 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void duplicateExpression9() {
+        // #9320
+        check("void f() {\n"
+              "  uint16_t x = 1000;\n"
+              "  uint8_t y = x;\n"
+              "  if (x != y) {}\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void duplicateExpressionLoop() {
         check("void f() {\n"
               "    int a = 1;\n"